Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: ex-meridian problem
    From: Bruce Stark
    Date: 2001 Feb 17, 3:54 PM

    Sometimes an experiment can help clarify things.
    
    Suppose our dead reckoning puts us about 30� N, 145� W. It's a little before
    noon. We get a true altitude of 69� 20'. The sun's declination is 10� N, his
    GHA 140�. With this data, using the Ex-meridian tables, we get a latitude of
    30� 8' north.
    
    But since we aren't sure of our DR longitude, we work the problem again using
    146� west. That gets a latitude of 29� 54'.
    
    Obviously, if we plotted this and drew a line from 30� 8' N, 145W to 29� 54'
    N, 146� W we'd have a chord of a circle. The sun's geographic position would
    be the center of the circle and his zenith distance the radius.
    
    Bruce
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site